Gas burner manifold for furnaces



Oct. 27, 1964 LAUNDER GAS BURNER MANIFOLD FOR FURNACES 2 Sheets-Shee t 1 Filed July 7, 1959 INVENTOR.

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GAS BURNER MANIFOLD FOR FURNACES Filed July '7, 1959 v 2 Sheets-Sheet 2 FIG.

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ERNIE Z. 140N051? MM/7W4" AGENT United States Fatent O 3,154,133 GAS BURNER MANIFOLD FOR FURNACES Ernie L. Launder, R0. Box 330, Montebello, Calif. Filed July 7, 1959, Ser. No. 825,609 14 Claims. (Cl. 158104) This invention relates to a gas burner manifold for furnaces and is particularly concerned with fuel piping in a multi-burner furnace and in which inefiiciencies ordinarily occur, it being a general object of this invention to correct operating deficiencies in a multi-burner furnace and so that maximum efficiency can be reliably attained.

Furnaces are employed widely and for varied purposes. In many instances relatively high temperatures are necessary and, for example, in heat treating units temperatures are maintained up to 2000 F. Although the gas burner manifold of the present invention is applicable generally to any type of furnace, it has been found particularly useful in connection with heat treating furnaces wherein high temperatures and efficiency are required. Therefore, the present invention will be described as it is applicable to a heat treating unit, it being understood that the manifold is broadly applicable to any furnace, or the like.

It has been found that a wide range of difficulties and inefficiencies develop and arise in the actual operation of high temperature furnaces. In a heat treating unit the furnace chamber is employed to receive a batch or load of articles to be heat treated, said articles being placed in the chamber in order to take up. and absorb heat. Therefore, it is important that the furnace be capable of recovery from the introduction of said loads of articles by bringing the load up to the desired temperature in the shortest possible length of time. In practice, when a load is introduced into a furnace preheated to the required temperature the load immediately absorbs heat and the temperature in the furnace suddenly drops, and this results in a lowering of temperature within the furnace chamber. The time that it takes to raise the temperature back to the original and required temperature is the recovery time, and it is important that the furnace operate efliciently during this recovery period, to shorten said period as much as possible.

In view of the foregoing requirements a typical heat treating unit involves a furnace that has a multiplicity of burners, in which case it is necessary to divide the fuel supply evenly among said burners. It is possible, with considerable complexity and expense, to have individual aspirators and fuel regulators for the separate burners, but a manifold is more commonly employed, supplied from a fuel supply line from and through a single aspirator, the separate burners being supplied individually from the manifold. An ordinary manifold, however, has been found to be deficient, not only in the sense that heating efliciency is lost, but also in the sense that actual physical damage to the furnace structure results, particularly damage to the burners and tubes and resulting in premature destruction thereof.

From observation of actual furnace installations operated under full time commercial conditions it was found that the furnaces were unable to combust the required volume of gas necessary to reach the desired heat without causing the flame to leave the burners, and this resulted in rapid deterioration of the burners and of the furnace tubes. Also, there was a noticeable inability to go from low fire to high fire without disturb ances or vice versa, all resulting in the flame leaving the tips of the burners. Further, the operating noise level of the furnaces was extremely high accompanied by mechanical and pneumatic vibrations of various fre- 3,154,133 Patented Oct. 27, 1964 ice quencies and harmonically conducted throughout the furnace and entire heat treating unit. As a matter of fact, the audible noise was so extreme as to require limiting of operations as much as possible, and the vibrational frequencies so extreme as to cause breakage of said critical parts of the furnace structure, namely, the radiant heating tubes. As a result, there was nonuniformi-ty of pressures at the burners and improper mixtures of gas and air, all to the end that the furnaces were obviously inefiicient and extremely slow on the recovery period.

Upon close examination, it has been determined that vibrational frequencies occurred in the fluid dynamics of the furnaces, resulting in extreme pneumatic and meohanical vibrations and a high level of noise. It became apparent, also, that the ordinary manifold allowed breathing or pulsating of fluid therein and this phenomenon resulted'in the flames leaving the burners. That is, the flames oscillated to and from the burner tips. Said breathing or pulsating is the result of the combustible mixture being allowed to expand and contract within the manifold chamber. As a result of said oscillation of the flame too much secondary air (oxygen was allowed. to enter the radiant heating tubes causing them .to oxidize, as well as to be dam-aged prematurely by mechanical vibrations resonating throughout the furnace structure.

An object of this invention is to provide a gas humermanifold for furnaces that enables the flame to remain or stay at the burners and not leave the same.-

Another object of this invention is to provide a gas burner manifold for furnaces that eliminates or materially reduces vibrations both in the fluid dynamics and in the structural. dynamics thereof. As a result of reduction in the generation of vibrational frequencies there is a resultant decrease in problems stemming from the harmonics as related thereto.

Still another object of this invention is to provide afurnace and burner structure that operates quietly and accompanied by efficiency.

It is still another object of this invention to provide a furnace and burner structure that operates without damaging effect upon the structure itself, especially the critical parts of the structure such-as, for example, .the burners and the radiant heating tubes.

It is an object of this invention to provide a gas burner manifold for furnaces that enables the furnace to be operated at a maximum efficiency in order to reduce recovery. periods to a minimum.

Further, it is an object of this invention to provide a manifold for the purposes thus far referred to that establishes uniformity of gas pressure, gas mixture, and gas flow, particularly at the burners and all to the end that vibrations and noise are substantially eliminated.-

The various objects and features of this invention will be fully understood from the following detailed descrip-- tion of the typical preferred form and application of the invention throughout which description reference is made to the accompanying drawings, in which:

FIG. 1 is a side elevation of a typical heat-treating unit of the type under consideration and showing the installation of the manifold of the invention as it is cooperatively related to said unit. FIG. 2 is a transverse'sectional view of the structure shown in FIG. 1 being a view taken as indicated by line 22 on- FIG. 1. FIG. 3 is an enlarged sectional view taken as indicated by line 33 on FIG. 2. FIG. 4 is a perspective view of the manifold that I provide and removed from the installation shown in FIGS. 1 and 2. FIG. 5 is a sectional view taken substantially as indicated by line 5--5' on FIG. 4. FIG. 6 is asectional view taken as indicated by line 66 3 on FIG. 2, and FIG. 7 is a sectional view taken as indicated by line 77 on FIG. 6.

In FIG. 1 of the drawings I have shown a typical heat treating unit X of the forced convection type and which is, or can be, completely automated. The unit shown is a controlled atmosphere metal treating unit for automatic processing of batches or loads of articles through heat and quench chambers for scale-free production. The heat treating unit is characterized by a closed heat chamber with forced convection atmospheric circulation and characterized by a multiplicity of gas-fired burners, each operating at a radiant heating tube. When in operation, a batch or load of metal articles is introduced into the heat chamber where they absorb heat, it being a primary objective to evenly fire the burners at the radiant tubes in order to recover in a minimum length of time.

The heat treating unit X involves a furnace section 11) and a quench section 11, said sections 1% and 11 being adjacently related so that loads of articles can be introduced into and passed through the unit X and from the section into the section 11. The furnace section 10 has a chamber 12 defined by surrounding walls of insulation 13, said chamber 12 being open at the front and inner ends thereof, there being a door 14 closing the front end of the chamber. The quench section 11 has a chamber 15 defined by surrounding walls 15, said chamber 15 being open at the inner and rear ends thereof, there being a door 17 closing the rear end of the chamber. The two chambers 12 and 15 are in communication with each other at their inner ends, respectively, and there is an intermediate door 18 that is used to isolate the two chambers from each other.

The unit X is of the forced convection type and includes a bafiie structure 19 that operates in conjunction with a circulating fan 20 to move and direct the atmosphere through the chamber 12. The atmosphere in the chamber 12 is controlled in which case it is necessary to isolate the burner combustion from the chamber and, therefore, the radiant tubes 21 are employed, each tube 21 being heated by a burner 22. As best illustrated in FIG. 2 of the drawings the tube 21 and burner 22 form assembly Y that extends through the chamber 12, said assembly Y being a vertically disposed flue-like assembly with the burner 22 at the lower end thereof and the tube 21 open at the top end to exhaust burnt gases.

The tube and burner assembly Y is a straight elongate structure that enters the chamber 12 through aligned top and bottom openings in the walls of the furnace section Iii. The assembly is supported by a base 23 that is fastened to the wall beneath the chamber 12, the burner 22 and radiant tubes 21 being sealed with the base in order to exclude outside atmosphere. The radiant tube 21 rests upon a gasket at the base 23 so that it too is sealed, said tube 21 being an imperforate element circular in cross section. The upper end of the radiant tube 21 is sealed with the Wall at the top of the chamber 12 by means of a bellows and gasket assembly 24, all so that the interior of the radiant tube 21 is isolated from the interior of the chamber 12. As shown, the burner 22 has a body that extends through the base 23 and has a burner tip above the base and centered within the radiant tube 21, the tube 21 being a ceramic tube adapted to be heated to high temperature and to radiate heat Within the chamber 12.

In accordance with the present invention, I provide the manifold Z that supplies the multiplicity of tube and burner assemblies Y, a usual furnace section 10 having twelve tube and burner assemblies with six assemblies along each side of the heating chamber 12. As illustrated in FIGS. 4-6, the manifold Z receives flow of mixed gas and air and distributes it equally to a multiplicity of burner supply ducts, for example, twelve individual supply ducts. It will be apparent, however, that the number of distributions does not affect the scope of the invention herein disclosed. In the particular case illustrated, where six burners 22 occur at each side of the furnace section It), I provide six laterally disposed burner supply ducts at each side of the manifold Z, with said manifold extending horizontally and longitudinally beneath the chamber 12 and between the two opposite side rows of burners 22.

The manifold Z involves, generally, a receiver A, a shield B and a plurality of supply ducts C. The receiver A is a chambered element that is supplied with a combustible mixture of gas and air from an aspirator S. The shield B which is provided in accordance with the present invention occupies its operating position within the chambered receiver A, and the burner supply ducts C are cooperatively related to the receiver A and shield B and evenly distribute the combustible mixture to the individual burners 22. In practice, flexible hoses 31 extend between the ducts C and the burners 22 in order to facilitate installation and to prevent transmission of any mechanical vibrations that may develop.

The aspirator S is shown in FIGS. 4 and 5 and involves a venturi-shaped body 31 that delivers an intimate mixture of gas and air into the receiver A. The particular aspirator shown is supplied by gas at a nominal or no pressure through a supply pipe 33. The air under pressure enters the body 31 and passes through an orifice 34 that is encompased by an annular opening 35 in communication with the gas supply pipe 33. There is a valve adjustment at 36 to control admission of gas through the opening 35 and into the orifice 34, and there is a displacement rod 37 that extends centrally through the orifice 34 to establish the desired air movement through the orifice. It will be apparent that the outlet end 38 of the aspirator S delivers a mixture of gas and air as circumstances require.

The receiver A of the manifold Z is in open communication with the outlet end 38 of the aspirator S and is supplied with a combustible mixture of gas and air that flows through the manifold and into the individual burner supply ducts C. The manifold Z is a shell-like element, elongate in form and configuration and closed at its opposite ends to establish a chamber 40 therein. Therefore, the manifold has a wall 41, preferably cylindrical in cross-section, and it has opposite end walls 42 and 43 closing the manifold ends and establishing the chamber 49. The end walls 42 and 43 are rounded or semi-spherically shaped, as shown in FIG. 6, in order to avoid corners within the chamber 40. Thus, the interior of the receiver A, in its preferred form, is round in crosssection with substantially half round ends, and the receiver has an inlet opening 44- intermediate the opposite ends and formed in the wall 41 to open laterally. As shown, the opening 44 opens downwardly and into a supply duct 45 that extends laterally of the manifold and connects with the outlet end 38 of the aspirator S.

In carrying out the invention it has been found advisable to limit the longitudinal extent of the receiver A in order to minimize the volume of fluid Within the chamber 41) and to assure even distribution to the multiplicity of burners 22. Therefore, in the particular case illustrated, where six tube and burner assemblies Y occur in a row, I prefer to employ two receivers A, each supplying three tube and burner assemblies (that its, three assemblies at each side of the furnace section 10 and six altogether). In FIG. 4 I have shown such an arrangement of receivers A, said receivers being aligned and adjacent each other in end to end relationship. Since it is desired to supply the two receivers from a single aspirator S, the supply ducts 45, one from each receiver A, join with a header 46 that is supplied from the outlet end 33 of the aspirator through a common supply duct 45'. More specifically, the header 46 is a straight elongate tubular part in open communication with the duct 45', intermediate the opposite ends of the header, and said header 46 is in open communication with the two supply ducts 45 through suitable elbows 47 and 48. The elements involved are symmetrically formed and oppositely and identically arranged so that flow is equally distributed between the opposite ends of the header 46, and to the end that there is an equal supply of gas and air mixture to the two like, or identical, receivers A.

The two receivers A are identicaly formed, as above indicated, in which case the shield B and supply ducts C are also identicallyincorporated therein, respectively. As shown in FIGS. 6 and 7, the shield B is a baffle-like element fixedly supported in operating position within the chamber 49. The shield B can vary in shape and details of construction and, generally, is a plate 59 extending longitudinally of the receiver and spaced from the wall 41 thereof, and at the side of the receiver A opposite the inlet opening 44. In the case under consideration, where the receiver A is round in cross section, the plate 50 is arcuate in cross section and is curved substantially concentrically with the wall 41 to be evenly spaced therefrom. In practice, the said curved plate 50 is semi-circular in cross section, so that it extends downwardly at each side to establish oposite edges 51 substantially midway between the top and bottom of the receiver A. Further, the plate 59 is substantially coextensive with the length of the receiver A and terminates at opposite ends 52 and 53 spaced somewhat inward of the ends 42 and 43 of the receiver A, respectively. The plate 50 is suitably anchored in operating position by spacers 54 and, in practice, is spaced inwardly of the wall 41 about one-sixth of the diameter of the receiver A, as shown in FIG. 7.

The supply ducts C are provided to distribute the flow of gas and air mixture to the several individual burners 22 via the hoses 30, there being suitable hose connections 60 and 61 coupling the ends of the hoses to the ducts C and burner bodies, respectively (see FIG. 12). As shown throughout the drawings, the ducts C are evenly distributed relative to the receiver chamber 40 and each duct is a tube fitting 62 that projects laterally of the wall 41. In the case illustrated there are six fittings 62, three at each side of the receiver A, said fittings being in open communication with the interior of the chamber 40. In accordance with the invention, the fittings 62 project laterally on axes in a common horizontally disposed plane that occurs substantially midway between the top and bottom of the receiver A and substantially coincidental with the lower edges 51 of the plate 50. Thus, the tubular fittings 62 draw gas and air mixture from below the plate 50 and also from between the plate 50 and wall 41 at the upper portion of the chamber 40.

The manifold Z, hereinabove described, is arranged and supported by suitable brackets to occur at or adjacent the bottom of the furnace section 10. In the particular case under consideration, where twelve tube and burner assemblies Y are involved, a manifold Z having an equal number, or twelve, burner supply ducts C is provided. More particularly, a manifold involving a pair of receivers A is provided in order to assure even distribution of the combustible mixture, as above described. With the manifold Z located beneath the furnace section It), hoses 3%) of equal length are extended from the ducts C to the individual burners 22, to the end that the installation is symmetrical and balanced. Further, the manifold receivers are connected to the delivery end 38 of the aspirator S through the supply ducts 45 joined into the common supply duct 45 by means of the header 46. Thus, the gas and air mixture delivered by the aspirator is communicated to the chamber or chambers to be distributed,

evenly to the individual burners 22.

Heretofore, pneumatic vibrations and harmonic mechanical vibrations, accompanied by reverberations, were generated with increasing force as larger volumes of mixture were passed through an ordinary manifold to the burners. In other words, when it was desired to go to high fire and to operate the furnace at or near top capacity, extreme vibrations, reverberations and noise developed. As a result, and as clearly set forth at the outsetof this specification, said vibrations, etc. caused irregularity of performance at the burners and caused fracturing and breakage of parts, namely, the ceramic tubes. Said irregularity of performance resulted in a barrier to efiicient operation of the furnace and actually prevented passage therethrough of sufficient combustible mixture to operate at capacity. The said irregularity of performance and resulting deficiencies in operation was reflected in slow recovery periods.

By provision of and incorporation of the manifold Z that I provide, the above mentioned irregularity and deficiencies are substantiallyeliminated by damping out the pneumatic and mechanical vibrations, and thereby eliminating substantially all noise andreverberations that would normally occur as above set forth. Within the manifold Z of the present invention, the aspirated mixture of gas and air can be forced throughthe receiver A at capacity and distributed uniformly tothe multiplicity of burners 22, all without breathing or pulsating within the manifold chamber and without generation of resonant frequencies that heretofore caused the flames to leave the burner tips. By providing the shield B-the mixture entering the chamber 40 is deflected so as to spread out in both directions toward the opposite ends of the receiver A, and so as to flow upwardly and over the top of the shield B. The shield-Bacts asa bailie that uniform ly directs flow and mufiles vibrations. As a result of'the provision of the shield B within the receiver A, as above described, pressures are uniform throughout the length of the receiver and so that even flow without vibrational frequencies is established through the supply ducts C and to the burners 22. Said even flow to the burners 22 assures that the flames remain or stay at the burner tips, without oscillations to and from said tips, and results in quiet, reliable operation at top capacity and without use of excess fuel. Together with quietness of operation, the elimination of vibrations results in extended'life ofthe critical furnace parts including the burner tips and, namely, the radiant heat tubes 21-.

Having described only a typical preferred form of my invention I do not wish to be limited or restricted to the specific details herein set forth, but I wish to reserve to myself any variations or modifications that may appear to those skilled in the art and which fall within the scope of the following claims:

Having described'my invention, I claim:

1. A manifold for receiving fluid flow and distributing it equally to a multiplicity of individual supply ducts and for damping out pneumatic and mechanical vibrations, and including, an elongate tubular receiver with side walls and closed at its opposite ends to have a chamber therein andwith a lateral inlet opening in one side wall thereof intermediate said ends, a shield extending longitudinally of thereceiver within said chamber and opposite the inlet opening and spaced from the side wall opposite the inlet opening, and a multiplicity of supply ducts opening laterally into said chamber through a side wall of the receiver.

2. A- manifold forreceiving fluid How and distributing it equally to a multiplicity of individual supply ducts and for damping out pneumatic and mechanical vibrations, and including, an elongate tubular receiver with side walls and closed at its opposite ends to have a chamber therein and with a lateral inlet opening in one side wall thereof intermediate said ends, a shield extending longitudinally of the receiver within said chamber and opposite the inlet opening and spaced from the side wall opposite the inlet opening, and a multiplicity of supplyducts opening laterally into said chamber through a side wall of the receiver, the opening of each supplyduct into the chamber being at least partially covered by the saidshield.

3. A manifold for receiving fluid flow and distributing it equally to a multiplicity of individual supply ducts and for damping out pneumatic and mechanical vibrations, and including, an elongate tubular receiver with'side walls and closed at its opposite ends to have a chamber therein and with a lateral inlet opening in one side wall thereof intermediate said ends, a shield extending longitudinally of the receiver within said chamber and opposite the inlet opening and spaced from the side wall opposite the inlet opening, and a multiplicity of supply ducts opening laterally into said chamber through a side wall of the receiver, the opening of each supply duct into the chamber being covered by a portion of the shield.

4. A manifold for receiving fluid flow and distributing it equally to a multiplicity of individual supply ducts and for damping out pneumatic and mechanical vibrations, and including, an elongate tubular receiver with side walls and closed at its opposite ends to have a chamber therein and with a lateral inlet opening in one side Wall thereof intermediate said ends, a shield extending longitudinally of the receiver within said chamber and opposite the inlet opening and spaced from the side Wall opposite the inlet opening, said shield comprising a plate formed to be uniformly spaced from the Walls of the receiver and a multiplicity of supply ducts opening laterally into said chamber through a side Wall of the receiver.

5. A manifold for receiving fluid flow and distributing it equally to a multiplicity of individual supply ducts and for damping out pneumatic and mechanical vibrations, and including, an elongate tubular receiver with side walls and closed at its opposite ends to have a chamber therein and with a lateral inlet opening in one side wall thereof intermediate said ends, a shield extending longitudinally of the receiver Within said chamber and opposite the inlet opening and spaced from the side wall opposite the inlet opening, said shield comprising a plate formed to be uniformly spaced from the walls of the receiver and with opposite edges intermediate the inlet opening and side wall opposite said inlet opening, and a multiplicity of supply ducts opening laterally into said chamber through a side wall of the receiver.

6. A manifold for receiving fluid flow and distributing it equally to a multiplicity of individual supply ducts and for damping out pneumatic and mechanical vibrations, and including, an elongate tubular receiver with side Walls and closed at its opposite ends to have a chamber therein and with a lateral inlet opening in one side Wall thereof intermediate said ends, a shield extending longitudinally of the receiver within said chamber and opposite the inlet opening and spaced from the side wall opposite the inlet opening, said shield comprising a plate formed to be uniformly spaced from the walls of the receiver and with opposite edges intermediate the inlet opening and side Wall opposite said inlet opening, and a multiplicity of supply ducts opening laterally into said chamber through a side wall of the receiver, the opening of each supply duct into the chamber being at least partially covered by an edge of the said shield.

7. A manifold for receiving fluid flow and distributing it equally to a multiplicity of individual supply ducts and for damping out pneumatic and mechanical vibrations, and including, an elongate tubular receiver with side Walls and closed at its opposite ends to have a chamber therein and with a lateral inlet opening in one side wall thereof intermediate said ends, a shield extending longitudinally of the receiver within said chamber and opposite the inlet opening and spaced from the side Wall opposite the inlet opening, said shield comprising a plate formed to be uniformly spaced from the walls of the receiver .and with opposite edges intermediate the inlet opening and side wall opposite said inlet opening, and a multiplicity of supply ducts opening laterally into said chamber through a side wall of the receiver, the opening of each supply duct into the chamber being at the edge of the shield and covered by a portion thereof.

8. A manifold for receiving fluid flow and distributing it equally to a multiplicity of individual supply ducts and for damping out pneumatic and mechanical vibrations, and including, an elongate cylindrical receiver closed at its opposite ends and having a chamber therein and with a lateral inlet opening in one side thereof intermediate said ends, an arcuate shield extending longitudinally within the chamber of the receiver and opposite the inlet opening and spaced from the side thereof opposite the inlet opening, and a multiplicity of supply ducts opening laterally into said chamber from the side of the receiver.

9. A manifold for receiving fluid flow and distributing it equally to a multiplicity of individual supply ducts and for damping out pneumatic and mechanical vibrations, and including, an elongate cylindrical receiver closed at its opposite ends and having a chamber therein and with a lateral inlet opening in one side thereof intermediate said ends, an arcuate shield extending longitudinally within the chamber of the receiver and spaced from the side thereof opposite the inlet opening, said shield comprising a plate formed to be uniformly spaced from the walls of the receiver and opposite the inlet opening and with opposite edges intermediate the inlet opening and side Wall opposite said inlet opening, and a multiplicity of supply ducts opening laterally into said chamber from the side of the receiver.

10. A manifold for receiving fluid flow and distributing it equally to a multiplicity of individual supply ducts and for damping out pneumatic and mechanical vibrations, and including, an elongate cylindrical receiver closed at its opposite ends and having a chamber therein and With a lateral inlet opening in one side thereof intermediate said ends, an arcuate shield extending longitudinally within the chamber of the receiver and spaced from the side thereof opposite the inlet opening, said shield comprising a plate formed to be uniformly spaced from the walls of the receiver and opposite the inlet opening and with opposite edges intermediate the inlet opening and side wall opposite said inlet opening, and a multiplicity of supply ducts opening laterally into said chamber from the side of the receiver, the opening of each supply duct into the chamber being at the edge of the shield and covered by a portion thereof.

11. A gas fired furnace of the character described including, a multiplicity of like burners, a common combustible gas supply, and a noise suppression manifold for receiving said combustible gas from the supply and distributing it equally to the individual burners and for damping out pneumatic and mechanical vibrations to prevent generation of the same in said furnace, and comprising, an elongate receiver of tubular cross section and closed at its opposite ends and with a lateral inlet opening in one side thereof intermediate said ends, a shield within the receiver and extending longitudinally thereof and opposite the inlet opening and spaced from one side of the receiver opposite the inlet opening, and a multiplicity of supply ducts opening laterally from a side of the receiver, and extending to the individual burners.

12. A gas fired furnace of the character described including, a multiplicity of like burners, a common combustible gas supply, and a noise suppression manifold for receiving said combustible gas from the supply and distributing it equally to the individual burners and for damping out pneumatic and mechanical vibrations to prevent generation of the same in said furnace, and comprising an elongate tubular receiver with side walls and closed at its opposite ends to have a chamber therein and with a lateral inlet opening in one side Wall thereof intermediate said ends, a shield extending longitudinally of the receiver within said chamber and opposite the inlet opening and spaced from the side wall opposite the inlet opening, and a multiplicity of supply ducts opening laterally into said chamber through a side Wall of the receiver and extending to the individual burners.

13. A gas fired furnace of the character described including, a multiplicity of like burners, a common combustible gas supply, and a noise suppression manifold for receiving said combustible gas from the supply and distributing it equally to the individual burners and for damping out pneumatic and mechanical vibrations to prevent generation of the same in said furnace, and comprising an elongate tubular receiver with side walls and closed at its opposite ends to have a chamber therein and with a lateral inlet opening in one side wall thereof intermediate said ends, a shield extending longitudinally of the receiver within said chamber and opposite the inlet opening and spaced from the side wall opposite the inlet opening and a multiplicity of supply ducts opening laterally into said chamber through a side Wall of the receiver, the opening of each supply duct into the chamber being covered by a portion of the shield, and extending to the individual burners.

14. A gas fired furnace of the character described including, a multiplicity of like burners, a common combustible gas supply, and a noise suppression manifold for receiving said combustible gas from the supply and distributing it equally to the individual burners and for damping out pneumatic and mechanical vibrations to prevent generation of the same in said furnace, and comprising an elongate tubular receiver with side walls and closed at its opposite ends to have a chamber therein and with a lateral inlet opening in one side wall thereof intermediate said ends, a shield extending longitudinally of the receiver Within said chamber and opposite the inlet opening and spaced from the side wall opposite the 10 inlet opening, said shield comprising a plate formed to be uniformly spaced from the wall of the receiver, and a multiplicity of supply ducts opening laterally into said chamber through a side wall of the receiver and extending to the individual burners.

References Cited in the file of this patent UNITED STATES PATENTS 284,814 Burton Sept. 11, 1883 366,780 Love et al. July 19, 1887 746,992 Rice Dec. 15, 1903 753,871 Fuller Mar. 8, 1904 859,486 CrOnwall July 9, 1907 1,630,878 Wilson May 31, 1927 1,900,217 Adams Mar. 7, 1933 2,068,477 Woodson Jan. 19, 1937 2,142,014 Zink Dec. 27, 1938 2,224,133 Biddle Dec. 10, 1940 2,389,270 Miller Nov. 20, 1945 2,488,218 McCullum Nov. 15, 1949 2,755,851 Dow et al July 24, 1956 FOREIGN PATENTS 18,411 Great Britain of 1898 206,354 Great Britain Nov. 8, 1923 

1. A MANIFOLD FOR RECEIVING FLUID FLOW AND DISTRIBUTING IT EQUALLY TO A MULTIPLICITY OF INDIVIDUAL SUPPLY DUCTS AND FOR DAMPING OUT PNEUMATIC AND MECHANICAL VIBRATIONS, AND INCLUDING, AN ELONGATE TUBULAR RECEIVER WITH SIDE WALLS AND CLOSED AT ITS OPPOSITE ENDS TO HAVE A CHAMBER THEREIN AND WITH A LATERAL INLET OPENING IN ONE SIDE WALL THEREOF INTERMEDIATE SAID ENDS, A SHIELD EXTENDING LONGITUDINALLY OF THE RECEIVER WITHIN SAID CHAMBER AND OPPOSITE THE INLET OPENING AND SPACED FROM THE SIDE WALL OPPOSITE THE INLET OPENING, AND A MULTIPLICITY OF SUPPLY DUCTS OPENING LATERALLY INTO SAID CHAMBER THROUGH A SIDE WALL OF THE RECEIVER. 